This invention relates to ladders and more particularly, to flexible rope ladders.
There has recently developed a recognition of the need for a variety of safety equipment, especially adapted for home use. In short, there is a greater degree of public recognition of safety requirements for homeowners, apartment dwellers, and for commercial tenants in large multi-story commercial facilities. This is especially true in connection with fire safety equipment, in view of the excessive numbers of fires which occur yearly, and the numbers of people who are injured or killed in connection with home and apartment fires.
In this connection, a variety of escape devices have been manufactured and sold particularly to homeowners and apartment dwellers, for use in connection with fires. A typical piece of equipment, which is currently available, consists of a ladder formed by a pair of parallel chains having wood or metal slats interconnecting the parallel chains thereby to create a ladder which may be employed in the event of an emergency. The top of the ladder generally has a rigid metal framework which is intended to be hooked over the window sill, and the user then simply throwing the lower portion of the ladder out of the window until the same extends downwardly the full length thereof.
Another version of an escape ladder is known and presently commercially available, and is basically similar to the chain configuration described above, with the exception that rope is used for the long parallel sides of the ladder, with shorter lengths of rope being tied between the parallel lengths to form steps. Once again, either a framework is emloyed at the top end of the ladder, or each of the upper ends of the long parallel lengths of rope are provided with eyelets thereby intending that the upper end of the ladder be connected to an internal structure, with the balance of the ladder being displayed from the window to form an escape route.
Insofar as the chain ladder is concerned, one of the difficulties which has been observed is the fact that a chain ladder having rigid sections between the lengths of chain is not easily compacted and stored internally of the house. Even when totally folded, a chain ladder having rigid steps consumes a great deal of space, and often, the chains will interwind such that in an emergency, it is often necessary to unravel the lengths of chain so that the ladder may be fully extended. In addition, a ladder formed of chains and rigid cross members is extremely heavy, the weight being proportional to the size of the chain lengths, and the overall length of the ladder. Hence, small children or elderly persons may not be able to lift and manipulate the ladder in an emergency in order to deploy the same for emergency use. Furthermore, should the weight of the chain ladder and supporting framework be excessive, and the ladder connected to a wooden window sill, it is feasible that in older structures where the window sill is rotted or burned away, the ladder could tear loose injuring the users thereof during the emergency exit. Hence, there are problems associated with the chain-type rigid emergency ladders presently available.
Insofar as the flexible rope-type ladder is concerned, typically the rope pieces creating the steps are interconnected to the parallel lengths of rope by means of knots, and hence, the ladder is only as strong as the knots holding the cross pieces in position. In addition, typically such ladders are made of a nylon rope as opposed to hemp, with nylon having the tendency to curl and retain a curled posture when stored for long periods of time. Hence, when an emergency use does arise, nylon rope ladders tend to be difficult to unfold and do not always present an easily observable ladder configuration when in use. Finally, it is also known that when one attempts to use a rope ladder having rope pieces as cross members, it may well be difficult for the user to manipulate his legs from rope member to rope member, since the rope members have a tendency to buoy in the middle portion drawing the parallel side lengths together.
A variation of the flexible rope ladder employs two parallel lengths of rope as the side members, and a length of wooden pieces interposed between the parallel sides. The wooden steps generally have a hole drilled in each of the ends, such that the rope members may be inserted therethrough, and the step being held in position by means of a knot appropriately tied at predetermined distances along each of the two parallel lengths of rope such that the wooden slats are held in position. This type of ladder is more advantageous than the chain ladders since the rope will not have a tendency to intertwine and "hang up" on itself, while still providing the user with a rigid step to employ during an emergency exit. However, ladders of this type are similarly bulky to store, and again, if the rope portion of the ladder is made from a nylon-type or synthetic plastic-type material, when stored for long periods of time in a folded position, the synthetic resins have a tendency to retain a curled or looped configuration such that when the ladder is used in an emergency, the ladder will often not straighten out when deployed in its use position.
In accordance with the present invention, it is intended to create a flexible rope ladder which permits the user to have a secure footing when utilizing the ladder as an escape means, while at the same time permitting ease of compactness and storage during non-use. In addition, the rope ladder of the present invention is intended to be easily connected to any supporting structure internally of the house, and once deployed, to basically assume its intended vertical position down the length of the home, building, or other structure from which it is utilized. In addition, the mode of construction of the rope ladder of the present invention insures that each of the foot rests is securely retained to the main rope such that during use, there is a minimum of deformity in the ladder in order to facilitate the ability of the user to quickly manipulate himself down the rope ladder during an emergency exit.
In accordance with the above improvements, the flexible rope ladder of the present invention contemplates utilizing a main piece of three strand twisted rope, formed of either hemp or plastic, with a plurality of loops intertwined to the main rope, the plurality of loops being positioned along the length of the main rope thereby to form hand grasps and foot rests along the entire length of the main rope. In addition, the loops are intertwined to the main loop in left/right alternate configuration such that even should the rope ladder twist or turn during use, there is always one loop disposed in a 180.degree. juxtaposition relative to the previous vertically disposed loop. Another advantage obtained by employing a flexible rope of the construction contemplated by the present invention is that the entire rope ladder may be made of less material, thereby being more easily compacted and stored, while at the same time, being easier to manipulate since there is less material involved in the entire construction of the ladder. Hence, the rope ladder of the present invention is more readily and easily usable by small children and elderly people then the rope ladders heretofore known.